1. Field of the Invention
The present invention relates to dobbies and other weaving mechanisms to form the shed on weaving looms and it relates more specifically to the actuating mechanisms of electromagnetic selection which, in conjunction with the reading-in devices, control the mechanisms of this type depending on the design of the fabric during the weaving process.
2. Description of the Related Art
The document FR-A-2 515 703 (STAUBLI) describes an actuating mechanism of such type, that comprises as many electromagnets as there are heald shafts of the mechanism, that is to say, of amplifying systems and of heddle frames in the loom. The electromagnets, fed by the reading-in device, depending on the weave program, are installed on one only chassis that is driven by an oscillating motion connected to that of the mechanism and that is provided, each heddle, with a pivoting selector linked to elastic means that cause to separate it from the poles of attraction of the electromagnet in question. Thus, each selector is driven by an alternate displacement that cyclicly draws it closer and separates it from the rods of the two actuating mechanisms that effectuate the control of the contemplated amplifier system; the selection between the two elements of each pair is made by the respective electromagnet, depending on whether or not it is fed by the reading-in device of the mechanism.
Experience has shown that at the very high operating speeds, required in the future for the looms and the thereto associated weave mechanisms, the moveable armature that is part of every selector will strongly strike against the stationary armature of the electromagnet. These repeated impacts cause a relatively quick wear and tear on the assembly of the mechanism and moreover, in addition to considerable noise, give rise to vibrations that interfere with the operation of the mechanism and cause weaving defects. The practical disadvantages subsist even when the central section of each moveable armature is installed on a pivot firmly affixed to the body of the selector.